Fuel Injection Valve

ABSTRACT

Stable spray characteristics (particle size, directivity, divergence angle of spray, and penetration force) are provided for individual nozzle holes, flows of fuel toward the nozzle holes are not interfered with each other, and further spray characteristics can arbitrarily be altered at respective nozzle holes. 
     A whirler  11  for providing a whirling force to fuel is provided, and a whirl flow is formed in a cavity  20  downstream of a seal portion of a needle valve  16 . A plurality of nozzle holes  13  are formed in an orifice plate  14 , and openings on the cavity  20  side of the nozzle holes  13  are formed on substantially the same diameter with respect to the central axis of a fuel injection valve  1 . Thus it becomes possible to cause fuel having inflow angle and high flow velocity to flow into the openings of the nozzle holes  13 . Furthermore, in the vicinity of the openings of the nozzle holes  13 , fuel having high flow velocity flows in only on one side with respect to the cross section of the nozzle holes, so that contraction flow is generated in the nozzle holes  13 , and atomization is achieved as well.

TECHNICAL FIELD

The present invention relates to a fuel injection valve.

BACKGROUND ART

As a conventional fuel injection valve making direct injection into acylinder, there has been proposed a fuel injection valve that is capableof making injection with respect to any target position, without beingaffected by air flow in the cylinder, and further that includes aplurality of nozzle holes each having a small diameter. In such a fuelinjection valve, to make smooth injection with respect to respectivelydifferent target positions, the configuration of a cavity, which issituated from a seal portion of a valve to numerous nozzle holes, andthe direction of nozzle holes are varied.

However, in such a case, depending on layout of respective nozzle holesand direction of respective nozzle holes, there are different flows offuel flow from the cavity to the nozzle holes. Consequently, to obtainstable spray characteristics (particle size, directivity, divergenceangle of spray, and penetration force) at respective nozzle holes, it isnecessary to repeat test or the like, thus a large number of time isrequired.

For example, there has been conventionally proposed a fuel injectionvalve, which comprises a valve body including a hole and a cavity thatare formed in a valve seat, a plate that is joined to the cavity bywelding, as well as includes a plurality of nozzle holes, and a valveelement that moves up and down along the central axis of the valve bodyto open and close the hole, and in which the atomization of spray isachieved by designing the structures of the nozzle hole plate and thecavity (refer to Patent Document 1).

In such a fuel injection valve, when setting the configuration of nozzleholes and the angle of the nozzle holes individually at respectivenozzle holes, the flows of fuel from the cavity to the nozzle holes willbe changed at each of the nozzle holes respectively. Hence a problemexists in that the nozzle holes have respectively different spraycharacteristics (particle size, directivity, divergence angle of spray,and penetration force).

Furthermore, there has been proposed another fuel injection nozzle inwhich whirling means is located at the end portion of a needle (refer toPatent Document 2).

In this case, even if a whirling force is generated in fuel, since thenozzle holes are positioned in the center of a cavity, it is difficultto construct the nozzle holes for making injection with respect todifferent positions. Furthermore, the strength of a whirling force islargely affected by a centrifugal force, so that the whirling forcecomes to be smaller in the central portion of the cavity. Moreover, thediameter of nozzle holes is apparently smaller as compared with thediameter of a cavity, and thus a whirling force having been generated inthe cavity is largely decreased when fuel flows into the nozzle holes.Consequently, a problem exists in that effective whirling force cannotbe obtained.

Moreover, there has been provided a fuel injection valve in which aplurality of nozzle holes are formed in a measuring plate, as well as awhirl flow-generating groove is formed on the top of the measuring plate(refer to Patent Document 3).

Providing only such a whirl flow-generating groove raises thepossibility that there is some fuel not passing through the whirlflow-generating groove, but flowing directly into nozzle holes.Furthermore, in the case where there is provided any whirlflow-generating groove in order to generate the whirl flow upstream ofrespective nozzle holes, when a nozzle hole pitch is made small, flowsof fuel toward the adjacent nozzle holes are interfered with each other.Thus, a problem exists in the occurrence of fluctuation incharacteristics.

Further, it becomes necessary that the whirling groove and nozzle holesbe formed in the same measuring plate, thus arising a dimensionalproblem that the nozzle hole pate comes to be larger. Then, in case of alarge nozzle hole plate, the area presented to pressure is increasedwhen it is used under high fuel pressure. Consequently, a furtherproblem exists in lower reliability.

Patent Document 1: the Japanese Patent No. 3655905

Patent Document 2: the Japanese Patent Publication (unexamined) No.158989/1996

Patent Document 3: the Japanese Patent Publication (unexamined) No.340121/2004

DISCLOSURE OF INVENTION Problems to be Solved by the Invention

The problem to be solved is that stable spray characteristics (particlesize, directivity, and penetration force) cannot be obtained atrespective nozzle holes, and flows of fuel toward respective nozzleholes are interfered with each other. Moreover, a further problem exitsin that spray characteristics cannot be arbitrarily changed atrespective nozzle holes.

Means for Solving the Problems

In the present invention, there is provided a member giving a whirlingforce to fuel, the whirl flow is formed in a cavity downstream of a sealportion of a valve, and all nozzle holes are disposed at positions ofsubstantially the same diameter on the outer circumferential portion ofthe cavity where velocity of the flow is high. As a result of such aconstruction, it becomes possible to cause fuel of high flow velocityhaving an inflow angle to flow into openings of the nozzle holes.

In this construction, the inflow area of fuel when flowing into theopenings of the nozzle holes comes to be smaller, and further the flowvelocity thereof at the time of flowing into the nozzle holes becomeshigher. Furthermore, in the vicinity of the openings of the nozzleholes, fuel having higher flow velocity flows only in one side withrespect to the cross section of the nozzle holes, so that a contractionflow is generated in the nozzle holes, and further atomization isachieved as well. This phenomenon occurs only in the openings of thenozzle holes. Even if the direction of nozzle holes is changed, the sameeffect can be obtained.

Thus, in the case of relatively low pressure of fuel, even when nozzlehole directions are set with respect to predetermined respectivelydifferent targets, it is possible for respective nozzle holes to easilyobtain stable spray characteristics (particle size, directivity, andpenetration force).

ADVANTAGEOUS EFFECTS OF THE INVENTION

According to the invention, an advantage exists in that, in spite ofdifferent target positions to be subjected to injection at respectivenozzle holes, it is possible to suppress fluctuation in spraycharacteristics (particle size, directivity, divergence angle of spray,and penetration force) at respective nozzle holes, and to easily obtaina stable spray. Furthermore, in the conventional apparatuses, thegeneration of high fuel pressure (for example, 20 Mpa) is required tocarry out atomization. Whereas, according to the invention, a furtheradvantage exists in that about the same level of effect as that of theconventional apparatuses can be obtained under lower fuel pressure (forexample, 12 Mpa).

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1

A preferred embodiment according to the present invention is hereinafterdescribed with reference to the drawings.

FIG. 1 is a cross sectional view showing a fuel injection valveaccording to a first embodiment of the invention. FIG. 2 is a crosssectional view showing an end portion. In the drawings, a fuel injectionvalve 1 is constructed of a solenoid device 2 acting to generate anelectromagnetic force and a valve main body 3. In the solenoid device 2,a core 4 being a stator iron core, a ring 5 that is made of non-magneticmaterial, a holder 6 and a housing 7 form a magnetic circuit; and a coil9 that is connected to a terminal 8 is contained therein.

In the valve main body 3, there is provided a valve body 10. To thisvalve body 10, a whirler 11 acting to generate a whirling force in fuel,a valve seat 12 including a seat portion 12 a and a cylindrical portion12 b, as well as an orifice plate 14 that includes a plurality of nozzleholes 13 and measures the quantity of flow, are fixed.

A needle valve 16, being a valve element including an armature 15 actingas a moving iron core is supported in a slidable manner in the valvebody 10 and the whirler 11. By this needle valve 16 moving up and down,the valve is opened and closed. The compressive force of a spring 17,which is located in an internal part of the core 4, is adjusted by meansof a rod 18. Sealing properties of the valve element 16 are determinedby the compressive force provided by the spring 17 and the fluid forcethat is generated by the fact that the pressure of fuel is applied tothe valve element 16.

In response to a valve-opening signal from a control device, not shown,due to the fact that current is carried through the coil 9, the armature15, being a moving iron core, is attracted to the core 4, being a fixediron core. Then, at a time point when this attraction is larger than thecompressive force provided by the spring 17 and the fluid forcegenerated by fuel pressure, the valve is open. At this time, as to anopening area of the seat portion 12 a, a lift amount of the needle 16 isa distance until the needle 16 comes in contact with a stopper 19, sothat the opening area of the seat portion 12 a is determined by thislift amount. At the time of valve closing, current having been carriedthrough the coil 9 is interrupted, and thus the valve comes to be closeddue to the compressive force provided by the spring 17.

As for the flow of fuel herein, fuel, to which pressure has been appliedto a higher pressure by means of a fuel pump, not shown (for example, afuel pressure is 12 Mpa), is fed to the fuel injection valve 1 through adelivery pipe, not shown. At the time of valve closing, an internal partof the fuel injection valve 1 is filled with a high-pressure fuel up tothe needle valve 16 and the seat portion 12 a of the valve seat 12. Withvalve opening signal from the control device, not shown, the needle 16is lifted to valve-open position, and first a high-pressure fuel flowsinto a cavity 20 that is formed of the valve seat 12 downstream of theseat portion 12 a, and the orifice plate 14. After the cavity 20 hasbeen filled with the high-pressure fuel, the fuel is injected towardrespective predetermined target positions from the nozzle holes 13respectively.

FIG. 3 is a cross sectional view showing the end portion of a fuelinjection valve for explaining the situation of the flow of fuel. FIG. 4is a cross sectional view taken along the line A-A of FIG. 3. The fuelflowing in an internal part of the fuel injection valve 1 is providedwith a strong whirling force while passing through the whirler 11functioning to generate the whirl flow, and flows into the cavity 20 viathe needle valve 16 and the seat portion 12 a of the valve seat 12. Atthis time, the stable whirl flow will be generated in the entire cavity20. The fuel having been provided with the whirling force, then, comesto be a helical flow due to a centrifugal force, and pressed to theouter circumferential portion. The flow velocity of fuel becomes themaximum in the vicinity of the outer circumference of the cavity 20.

According to the invention, openings of respective nozzle holes 13facing to the cavity 20 are formed at the outer circumferential portionon the downstream side of the cavity 20, so that fuel having a certainamount of inflow angle and the maximum velocity flows into the openingsof the nozzle holes 13. That is, fuel including the main flow that isformed in the entire cavity 20 and is stable, comes to flow in each ofthe nozzle holes 13. FIG. 5( a) is a plan view showing the opening of anozzle hole 13. FIG. 5( b) is a perspective view showing the nozzle hole13. FIG. 6( a) is a plan view showing the opening according to aconventional nozzle hole. FIG. 6( b) is a perspective view showing theconventional nozzle hole.

As shown in FIG. 5, fuel flows into the nozzle holes 13 in the directionof being away from the center of the fuel injection valve 1, so that inthe vicinity of the opening of the nozzle holes 13 on the cavity 20side, the flow velocity on the wall of the side where fuel flows inbecomes higher, and the flow velocity on the opposite side thereof islower. The fuel comes to be in the state of being agitated in theinternal part of the nozzle holes 13.

According to the invention, flow rate is measured by means of theorifice plate 14, and pressure loss that is generated in the internalpart of a fuel injection valve 1 comes to be the maximum in the nozzleholes 13. Accordingly, even if fuel flows out from the nozzle holes 13,the whirl flow in the cavity 20 is not affected. Therefore, fuel flowsinto respective nozzle holes 13 in a stable manner irrespective of theangle from an opening to an outlet. Thus, even if the direction ofnozzle holes 13 is changed, only a direction with respect to any targetposition comes be changed, thus making it possible to easily set thenozzle holes 13 corresponding to individual target positionsrespectively without affecting fuel spray characteristics (particlesize, divergence angle of spray, and penetration force). In this manner,it is possible to set various spray characteristics by arbitrarilysetting angles from the opening to the outlet of respective nozzle holes13.

Due to the fact that fuel flows in the internal part of nozzle holes 13,it becomes possible to atomize fuel with low fuel pressure as comparedwith the conventional apparatuses. Further, as shown in FIG. 2, thecavity 20 is so configured that the inside diameter of the substantiallycylindrical portion 12 b is set to be smaller than the diameter of theseat portion 12 a, being a point of contact with the needle valve 16,and that the diameter φe of the valve seat 12 and the orifice plate 14being in contact is smaller than the inside diameter of thesubstantially cylindrical portion 12 b, whereby the channel area comesto be smaller by degrees toward the outer circumferential side, that is,for example, the cavity 20 is structured so as to be tapered on thedownstream side.

Thus, it is possible that fuel having been pressed to the outercircumferential surface of the cavity 20 is further pressurized by thecentrifugal force, and that the inflow angle of fuel is made larger withrespect to the axis of respective nozzle holes 13. Consequently, it ispossible to achieve further atomization of fuel.

FIGS. 7( a) and (b) are enlarged cross sectional views showing a taperedportion. FIG. 7( a) is an enlarged cross sectional view showing thetapered portion shown in FIG. 2. As shown in FIG. 7( b), the junctionbetween the substantially cylindrical portion 12 b and the taperedportion is constructed to be arc-shaped, and smoothly connected, therebyenabling to suppress the generation of fuel coming off when fuel flowsfrom the substantially cylindrical portion 12 b to the tapered portion.Owing to such construction, it is possible to make larger the fuelpressure and the flow velocity in the vicinity above the nozzle holes13, thus making it possible to achieve further atomization of fuel.

Due to the construction as described above, conventionally the fuelpressure of approximately 20 Mpa is required, while according to theinvention, about the same level of effect can be obtained with the fuelpressure of approximately 12 Mpa.

FIG. 8 is a cross sectional view showing the end portion of a fuelinjection valve. FIG. 9 is a cross sectional view taken along the lineB-B of FIG. 8. In the drawings, C is a taper angle; g is an angle ofinclination of the nozzle holes 13 with respect to the axial directionof a valve; m is an angle of inclination of the nozzle holes 13 withrespect to the radial direction; φd is a pitch diameter of the nozzleholes 13; φe is a diameter of the contact part between the valve seat 12and the orifice plate 14; φf is an inside diameter of the substantiallycylindrical portion 12 b; φh is an inside diameter of the nozzle holes13; j is a gap between the outermost diameter of the nozzle holes 13 andthe contact diameter φe; and k is a distance between pitches of thenozzle holes 13.

The flow velocity and the angle of inclination of fuel in the internalpart of the cavity 20, as well as the pressure of fuel above the nozzleholes 13 are affected by the configuration of the substantiallycylindrical portion 12 b, the taper angle C, and the pitch diameter φdof the nozzle holes 13. For example, in the case where a taper angle Cis small, the fuel pressure above the nozzle holes 13 is reduced. On thecontrary, in the case where the taper angle C is large, the resistancewhen fuel runs against the wall of the cavity 20 becomes larger, so thatthe flow velocity does not come to be larger.

Furthermore, the same problem as described above arises also in a ratiobetween the inside diameter of the substantially cylindrical portion 12b and the pitch diameter φd of the nozzle holes 13. It has beenacknowledged from test results that the balance between the fuelpressure and the flow velocity is appropriately achieved in the case inwhich a taper angle C is 120° to 150°.

Supposing that the contact part between the valve seat 12 and theorifice plate 14, and the outermost diameter portion of the nozzle holes13 come close, a problem exists in that the velocity of fuel isdecreased due to resistance on the wall in the vicinity of the wall ofthe cavity 20. To cope with this, it is necessary to provide a certaindifference between the contact diameter φe between the valve seat 12 andthe orifice plate 14, and the pitch diameter φd1 of the outermostdiameter of the nozzle holes 13.

It has been acknowledged from test results that, as the above-mentioneddifference, setting a difference of about the nozzle diameter φh isrequired. In addition, it has been acknowledged from test results thatsetting a ratio between the inside diameter φf the substantiallycylindrical portion 12 b and the pitch diameter φd of the nozzle holes13 to be 1.5 to 2.0 is suitable. Further, it is necessary that the pitchdiameter φd2 of the innermost diameter in the opening of the nozzleholes 13 facing the cavity 20 side is formed larger than the insidediameter Of the substantially cylindrical portion 12 b. Suchconstruction is employed because of smaller effect of the centrifugalforce, and lower flow velocity within the range of the inside diameterφf of the substantially cylindrical portion.

Moreover, the cavity 20 is formed on the downstream side of the seatportion 12 a, so that when the capacity of the cavity 20 is made larger,it will take a long time period for the cavity 20 to be filled withhigh-pressure fuel. Hence, a problem exists in a longer time perioduntil fuel injection. Furthermore, after a valve has been opened, aproblem exists in that the fuel left in the cavity 20 drips in theinternal part of the cylinder of an engine. It has been acknowledgedthat forming the inside diameter φf of the substantially cylindricalportion 12 b in the cavity 20 to be in the range of 0.6 mm to 1.0 mm issuitable.

Further, when the cross section of the substantially cylindrical portion12 b comes to be small as compared with the gross sectional area of thenozzle holes 13, the whirling force of fuel will be reduced. Therefore,it is necessary that the cross section of the cylindrical portion 12 bis not less than 1.5 times the gross sectional area of the nozzle holes13.

As to the layout of nozzle holes 13, when a distance k between pitchesof the adjacent nozzle holes is a small value, fuel to flow into theadjacent nozzle holes 13 will be interfered with each other, and thusfluctuation in inflow angle and flow velocity of fuel to flow into thenozzle holes 13 may take place between the nozzle holes 13.Consequently, fluctuation in spray characteristics will also arise, sothat it is necessary that the distance k between pitches of the nozzleholes 13 is set to be not less than 2.5 times the nozzle hole diameterφh.

FIG. 10, in the case of letting the diameter of nozzle holes 13 D (=φh),and the length of nozzle holes 13 L, is a graph showing a relationshipbetween L/D and spray characteristics (particle size, divergence angleof spray, and penetration force). As shown in FIG. 10, it is understoodthat particle size characteristics and a penetration force are improved,while a divergence angle of spray becomes smaller when L/D comes to belarger. Thus, it will be necessary to adjust L/D depending onspecification of engine.

According to the invention, as is understood from the situation of flowin the internal part of the nozzle holes 13 shown in FIG. 5, the flow offuel to be formed in the outlet of the nozzle holes 13 will be varied bychanging the setting of L/D. Accordingly, just changing L/D enables toalter spray characteristics (particle size, divergence angle of spray,and penetration force) in the relatively wide range.

With regard to the design of a cylinder injection engine, for example,in a center-injection system in which the fuel injection valve 1 islocated in the center of an engine, a distance from the fuel injectionvalve 1 to an ignition plug is short (e.g., approximately 15 mm). L/D isset to be small, whereby fuel is made to spray before it is rectified inthe internal part of the nozzle holes 13, thus making it possible toform a spray pattern in which penetration force is suppressed, anddivergence angle of spray is large.

Meanwhile, in a side-injection system in which the fuel injection valve1 is located on the side of an engine, a distance from the fuelinjection valve 1 to an ignition plug becomes longer (for example,approximately 40 mm). L/D is set to be larger, whereby fuel is made tospray in the state of being rectified to a certain degree in theinternal part of the nozzle holes 13, thus making it possible to form aspray pattern of large penetration force, and narrow spray angle. In thevalve according to the invention, it is suitable that L/D is set to beabout 2 to 4 in the former system, and L/D is set to be about 4 to 6 inthe latter system.

Concerning the layout of the nozzle holes 13, it is possible to adjustangles of the nozzle holes 13 so that lines made by extending the centerlines of respective nozzle holes 13 from the outlets are not crossedover each other. By employing such a construction, there will be nocollision of fuel having been sprayed from each of the nozzle holes.Then, a single outlet corresponds to a single target position, resultingin higher efficiency.

Embodiment 2

FIG. 11 is a cross sectional view showing an end portion of a fuelinjection valve according to a second embodiment of the invention.According to this second embodiment, there is provided a concave 14C ina part of the orifice plate 14, whereby a length L of a part of nozzleholes 13 is constructed to be different from length of the other nozzleholes. This construction changes L/D, so that it is possible to alterspray characteristics of the part of the nozzle holes 13.

Embodiment 3

FIG. 12 is a cross sectional view showing an end portion of a fuelinjection valve according to a third embodiment of the invention.According to this third embodiment, a valve seat and an orifice plateare configured to be an integral whole, and nozzle holes 13 are formedin the valve seat 12. Due to this construction, although the settingrange of a spray pattern to be formed with respective nozzle holes 13comes to be narrower, it is possible to reduce the number of parts, andto achieve cost reduction.

Embodiment 4

FIG. 13 is a cross sectional view showing an end portion of a fuelinjection valve according to a fourth embodiment of the invention.According to this fourth embodiment, there are provided whirling grooves21 in a part of the needle valve 16. Due to the formation ofwhirl-generating means at the needle valve 16 as described above, it ispossible to provide the same advantage as in the foregoing firstembodiment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross sectional view showing a fuel injection valve(Embodiment 1);

FIG. 2 is a cross sectional view showing an end portion of the fuelinjection valve (Embodiment 1);

FIG. 3 is a cross sectional view showing an end portion of the fuelinjection valve (Embodiment 1);

FIG. 4 is a cross sectional view taken along the line A-A of FIG. 3(Embodiment 1);

FIG. 5 is a plan view showing an opening of a nozzle hole (a), and aperspective view showing the nozzle hole (b) (Embodiment 1);

FIG. 6 is a plan view showing an opening of a conventional nozzle hole(a), and a perspective view showing the nozzle hole (b);

FIG. 7 is an enlarged cross sectional view showing the tapered portion(Embodiment 1);

FIG. 8 is a cross sectional view showing the end portion of the fuelinjection valve (Embodiment 1);

FIG. 9 is a cross sectional view taken along the line B-B of FIG. 8(Embodiment 1);

FIG. 10 is a graph showing the relationship between L/D and spraycharacteristics;

FIG. 11 is a cross sectional view showing an end portion of a fuelinjection valve (Embodiment 2);

FIG. 12 is a cross sectional view showing an end portion of a fuelinjection valve (Embodiment 3); and

FIG. 13 is a cross sectional view showing an end portion of a fuelinjection valve (Embodiment 4).

DESCRIPTION OF REFERENCE NUMERALS

-   1: fuel injection valve-   2: solenoid device-   10: valve body-   11: valve seat-   12 b: substantially cylindrical portion-   13: nozzle hole-   14: orifice plate-   16: valve element-   20: cavity

1-15. (canceled)
 16. A fuel injection valve including: a valve elementsupported to be capable of sliding in an internal part of a valve body;a valve seat with which said valve element is apart from or in contact;a whirling means that is disposed on the upstream side of said valveseat, and that provides a whirling force to fuel; and a solenoid devicefor causing said valve element to operate; wherein the downstream-sideend face of said valve seat and an orifice plate are fixed in closecontact, whereby a cavity is formed; and a plurality of nozzle holes areprovided in said orifice plate, and openings on said cavity side of saidnozzle holes are formed substantially on the same diameter with respectto a central axis of the fuel injection valve.
 17. The fuel injectionvalve according to claim 16, wherein said nozzle holes are formed at anyangle.
 18. The fuel injection valve according to claim 16, wherein aninside diameter of a substantially cylindrical portion that is formed insaid valve seat is formed to be smaller than a seat diameter, and acontact diameter between said valve seat and said orifice plate isformed to be larger than an inside diameter of said substantiallycylindrical portion, thereby being constructed such that a channel areacomes to be smaller by degrees toward the outer circumferential side.19. The fuel injection valve according to claim 18, wherein said cavityis constructed in a tapered configuration on the downstream side. 20.The fuel injection valve according to claim 19, wherein the junctionbetween said substantially cylindrical portion and tapered portion areformed to be a circular arc.
 21. The fuel injection valve according toclaim 19, wherein a taper angle is formed to be 120° to 150°.
 22. Thefuel injection valve according to claim 16, wherein a pitch diameter ofthe innermost diameter of the openings of said nozzle holes facing tosaid cavity side is formed to be larger than an inside diameter of saidsubstantially cylindrical portion formed in said valve seat, and acontact diameter between said valve seat and said orifice plate isformed to be larger than a pitch diameter of the outermost diameter ofsaid openings.
 23. The fuel injection valve according to claim 22,wherein a difference between the contact diameter between said valveseat and said orifice plate, and the pitch diameter of the outermostdiameter of said openings is substantially a nozzle hole diameter. 24.The fuel injection valve according to claim 16, wherein the insidediameter of said substantially cylindrical portion formed in said valveseat is formed to be 0.6 mm to 1.0 mm, and the pitch diameter of saidnozzle holes is formed to be 1.5 to 2.0 times the inside diameter ofsaid substantially cylindrical portion.
 25. The fuel injection valveaccording to claim 16, wherein a distance between pitches of said nozzleholes facing to said cavity side is not less than 2.5 times said nozzlehole diameter.
 26. The fuel injection valve according to claim 16,wherein said nozzle holes are disposed so that lines made by extendingcenter lines of said nozzle holes from outlets are not crossed over eachother.
 27. The fuel injection valve according to claim 16, wherein saidvalve seat and said orifice plate are formed to be an integral whole.28. The fuel injection valve according to claim 16, wherein, in the casewhere the fuel injection valve is mounted on the center of an engine,when letting a diameter of said nozzle holes D and a length of saidnozzle holes L, it is constructed to be 2≦L/D≦4.
 29. The fuel injectionvalve according to claim 16, wherein, in the case where the fuelinjection valve is mounted on the side of an engine, when letting adiameter of said nozzle holes D, and a length of said nozzle holes L, itis constructed to be 4≦L/D≦6.
 30. The fuel injection valve according toclaim 16, wherein a whirling groove is provided at a part of said valveelement.